98 ranger, 2.5L, Cranks, no start, no codes

[jbgood]

Hi everyone. I have a 98 Ranger 2.5L, 350,000 KM .Was driving ,started to bog down then stopped. Will crank ok, sometimes will start and run for a second then quits. I get no codes. Fuel pump relay seems ok KOEO can hear pump pressure build up for a couple of seconds. Last time this happened I was out of gas cause fuel gauge was lousy. I put in more fuel this time, added gas dry, but no start. Last year fuel pump ,IAC,TPS,fuel filter was replaced. Truck has been running fine until now. I am going out to replace fuel filter and check fuel pressure but was wondering if anyone can suggest any other things to check. Thank you.

 

[jbgood]

Hi. An update. I changed the fuel filter and swapped fuelpump relays but still no start. I then checked fuel pressure and only get about 0-8psi. Aha! I then unplugged the fuel harness connector and only got 6.5V between the power and ground on the harness according to the manual. So it looks like some rusty ground or connector. Will see.

 

[slolearner]

Problem

What was the final problem?

 

[slolearner]

Maf

A quick fix-it could be to clean your MAF relay. I had some bad drivability problems and it boiled down to the MAF relay being dirty.

 

[jbgood]

Well another update. I am trying to diagnose why I am getting 6.5 V on the PCM pin40 fuel pump wiring.( Engine cranks , will not start,NO codes. I have checked all B+ , continuity, fuses, swapped relays, etc.The PCM power relay is ok, operates the FPRelay fine, FPRelay gets the 12V but 6.5V out from the PCM pin40. All wiring from relay to fuelpump fine. The problem is no fuel pressure, 6.5V at fuel pump harness with a good ground. KOEO get 6.5V on FPRelay output even after the 2 second delay. I have read that it shoud be 0V after KOEO. I have seen other threads saying that the ccrm module may control some pcm and fuelpump functions ( Ford Escort) but cannot confirm if a 98 ranger has it (Haynes manual not too helpful) .If not, could the GEM cause the pcm to malfunction? Thank you.

 

[jbgood]

Well I finally found the problem , actually two problems! I unplugged the FPRelay ,ran 12V from the FPRelay B+ straight to the fuelpump. No start, no fuel pressure on the rail. However , now I finally got 12V at the fuelpump harness! I thought maybe it is the fuel pump afterall and perhaps IF it does not build up pressure, the PCM will give 6V instead of 12V with KOEO. I replaced the pump with the original one ( I replaced it last year just to be safe because of the km) . Voila it started, fuel pressure good. So I rewired things back up, reconnected the inertia switch which I had disconnected and no start again! Ran a wire from the relay box 12V out directly to the inertia switch wire to the fuel pump, and now it starts. So there is a problem with the wire between the fuelpump relay and the inertia switch and a bad fuel pump!